The fallout from a huge leak of Credit Suisse banking data threatened to damage Switzerland's entire financial sector on Monday after the European parliament's main political grouping raised the prospect of adding the country to a money-laundering blacklist. The European People's party (EPP), the largest political grouping of the European parliament, called for the EU to review its relationship with Switzerland and consider whether it should be added to its list of countries associated with a high risk of financial crime. Experts said that such a move would be a disaster for Switzerland's financial sector, which would face the kind of enhanced due diligence applied to transactions linked to rogue nations including Iran, Myanmar, Syria and North Korea. The EPP released the proposal after media outlets including the Guardian, Süddeutsche Zeitung, the Organized Crime and Corruption Reporting Project (OCCRP), and Le Monde revealed how a massive leak of Credit Suisse data had uncovered apparently widespread failures of due diligence by the bank. The investigation, called Suisse secrets, identified clients of the Swiss bank who had been involved in torture, drug trafficking, money laundering, corruption and other serious crimes. The country's addition to the EU high-risk third countries list would mean regulated professions, such as bankers, lawyers and accountants, would be required to conduct enhanced due diligence on any transaction or commercial relationship with a person or company in the country.